The concept of using pressurized cleaning fluid to provide the motive power for rotating a rotary spray cleaner is well known. A variety of different gear arrangements to accomplish this have been provided in the prior art. A particularly desirable goal in designing these spray cleaners is to make them small enough so that they can be inserted into the smaller access ports in the vessel to be cleaned. These access ports are usually about three inches in diameter in a tank car having compartments. Some solutions have even located the motive power source external to the vessel.
A continuing concern with using the pressurized fluid to provide the motive power is that the pressure required to be maintained for effective cleaning is so great that the rotational speed will be too fast. While gear reduction, even through the use of planetary gear drives, has been used, the gear box employed must be sufficiently shielded from the pressurized fluid, which may be caustic or corrosive, that rotational speed of the nozzles may be effectively changed only be changing fluid pressure or flow.
The long-felt need of the market, therefore, is for a compact rotary spray cleaner with significant gear reduction, but also with a generally accessible means being provided for additional interchangeable adjustment of the rotational speed of the nozzles.
One such attempt in the prior art is illustrated by U.S. Pat. No. 5,954,271, to Le. This patent goes to great lengths to isolate the gear drive so that it is not located between the fluid inlet and the nozzles, but is instead distal to the nozzles. This means that there is no ability to adjust rotational rate, and the gear drive is not easily interchanged in any case. Part of the reason why the gear drive is difficult to change is that it is positioned distal to the spray head.
It is therefore, an advantage of the present invention to provide a compact rotary spray cleaner which may be inserted into access ports no greater than three inches in diameter, use the pressurized cleaning fluid to provide motive power to rotate the nozzles through which the fluid exits the cleaner, and in which the rotational speed of the nozzles may be adjusted by a readily accessible means other than the pressure of the cleaning fluid.